Sofa



FIG. 1 is a perspective view of a sofa;

FIG. 2 is the top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a right side elevational view (left side elevational view is a mirror image thereof); and,

FIG. 5 is the rear elevational view thereof. 

CLAIM The ornamental design for a sofa, as shown and described. 